import {
  BufferGeometry,
  DataTexture3D,
  FileLoader,
  Float32BufferAttribute,
  LinearFilter,
  Loader,
  Mesh,
  MeshStandardMaterial,
  NearestFilter,
  RedFormat
} from '../../three.module.js';

class VOXLoader extends Loader {

  load(url, onLoad, onProgress, onError) {

    const scope = this;

    const loader = new FileLoader(scope.manager);
    loader.setPath(scope.path);
    loader.setResponseType('arraybuffer');
    loader.setRequestHeader(scope.requestHeader);
    loader.load(url, function (buffer) {

      try {

        onLoad(scope.parse(buffer));

      } catch (e) {

        if (onError) {

          onError(e);

        } else {

          console.error(e);

        }

        scope.manager.itemError(url);

      }

    }, onProgress, onError);

  }

  parse(buffer) {

    const data = new DataView(buffer);

    const id = data.getUint32(0, true);
    const version = data.getUint32(4, true);

    if (id !== 542658390 || version !== 150) {

      console.error('Not a valid VOX file');
      return;

    }

    const DEFAULT_PALETTE = [
      0x00000000, 0xffffffff, 0xffccffff, 0xff99ffff, 0xff66ffff, 0xff33ffff, 0xff00ffff, 0xffffccff,
      0xffccccff, 0xff99ccff, 0xff66ccff, 0xff33ccff, 0xff00ccff, 0xffff99ff, 0xffcc99ff, 0xff9999ff,
      0xff6699ff, 0xff3399ff, 0xff0099ff, 0xffff66ff, 0xffcc66ff, 0xff9966ff, 0xff6666ff, 0xff3366ff,
      0xff0066ff, 0xffff33ff, 0xffcc33ff, 0xff9933ff, 0xff6633ff, 0xff3333ff, 0xff0033ff, 0xffff00ff,
      0xffcc00ff, 0xff9900ff, 0xff6600ff, 0xff3300ff, 0xff0000ff, 0xffffffcc, 0xffccffcc, 0xff99ffcc,
      0xff66ffcc, 0xff33ffcc, 0xff00ffcc, 0xffffcccc, 0xffcccccc, 0xff99cccc, 0xff66cccc, 0xff33cccc,
      0xff00cccc, 0xffff99cc, 0xffcc99cc, 0xff9999cc, 0xff6699cc, 0xff3399cc, 0xff0099cc, 0xffff66cc,
      0xffcc66cc, 0xff9966cc, 0xff6666cc, 0xff3366cc, 0xff0066cc, 0xffff33cc, 0xffcc33cc, 0xff9933cc,
      0xff6633cc, 0xff3333cc, 0xff0033cc, 0xffff00cc, 0xffcc00cc, 0xff9900cc, 0xff6600cc, 0xff3300cc,
      0xff0000cc, 0xffffff99, 0xffccff99, 0xff99ff99, 0xff66ff99, 0xff33ff99, 0xff00ff99, 0xffffcc99,
      0xffcccc99, 0xff99cc99, 0xff66cc99, 0xff33cc99, 0xff00cc99, 0xffff9999, 0xffcc9999, 0xff999999,
      0xff669999, 0xff339999, 0xff009999, 0xffff6699, 0xffcc6699, 0xff996699, 0xff666699, 0xff336699,
      0xff006699, 0xffff3399, 0xffcc3399, 0xff993399, 0xff663399, 0xff333399, 0xff003399, 0xffff0099,
      0xffcc0099, 0xff990099, 0xff660099, 0xff330099, 0xff000099, 0xffffff66, 0xffccff66, 0xff99ff66,
      0xff66ff66, 0xff33ff66, 0xff00ff66, 0xffffcc66, 0xffcccc66, 0xff99cc66, 0xff66cc66, 0xff33cc66,
      0xff00cc66, 0xffff9966, 0xffcc9966, 0xff999966, 0xff669966, 0xff339966, 0xff009966, 0xffff6666,
      0xffcc6666, 0xff996666, 0xff666666, 0xff336666, 0xff006666, 0xffff3366, 0xffcc3366, 0xff993366,
      0xff663366, 0xff333366, 0xff003366, 0xffff0066, 0xffcc0066, 0xff990066, 0xff660066, 0xff330066,
      0xff000066, 0xffffff33, 0xffccff33, 0xff99ff33, 0xff66ff33, 0xff33ff33, 0xff00ff33, 0xffffcc33,
      0xffcccc33, 0xff99cc33, 0xff66cc33, 0xff33cc33, 0xff00cc33, 0xffff9933, 0xffcc9933, 0xff999933,
      0xff669933, 0xff339933, 0xff009933, 0xffff6633, 0xffcc6633, 0xff996633, 0xff666633, 0xff336633,
      0xff006633, 0xffff3333, 0xffcc3333, 0xff993333, 0xff663333, 0xff333333, 0xff003333, 0xffff0033,
      0xffcc0033, 0xff990033, 0xff660033, 0xff330033, 0xff000033, 0xffffff00, 0xffccff00, 0xff99ff00,
      0xff66ff00, 0xff33ff00, 0xff00ff00, 0xffffcc00, 0xffcccc00, 0xff99cc00, 0xff66cc00, 0xff33cc00,
      0xff00cc00, 0xffff9900, 0xffcc9900, 0xff999900, 0xff669900, 0xff339900, 0xff009900, 0xffff6600,
      0xffcc6600, 0xff996600, 0xff666600, 0xff336600, 0xff006600, 0xffff3300, 0xffcc3300, 0xff993300,
      0xff663300, 0xff333300, 0xff003300, 0xffff0000, 0xffcc0000, 0xff990000, 0xff660000, 0xff330000,
      0xff0000ee, 0xff0000dd, 0xff0000bb, 0xff0000aa, 0xff000088, 0xff000077, 0xff000055, 0xff000044,
      0xff000022, 0xff000011, 0xff00ee00, 0xff00dd00, 0xff00bb00, 0xff00aa00, 0xff008800, 0xff007700,
      0xff005500, 0xff004400, 0xff002200, 0xff001100, 0xffee0000, 0xffdd0000, 0xffbb0000, 0xffaa0000,
      0xff880000, 0xff770000, 0xff550000, 0xff440000, 0xff220000, 0xff110000, 0xffeeeeee, 0xffdddddd,
      0xffbbbbbb, 0xffaaaaaa, 0xff888888, 0xff777777, 0xff555555, 0xff444444, 0xff222222, 0xff111111
    ];

    let i = 8;

    let chunk;
    const chunks = [];

    while (i < data.byteLength) {

      let id = '';

      for (let j = 0; j < 4; j++) {

        id += String.fromCharCode(data.getUint8(i++, true));

      }

      const chunkSize = data.getUint32(i, true);
      i += 4;
      data.getUint32(i, true);
      i += 4; // childChunks

      if (id === 'SIZE') {

        const x = data.getUint32(i, true);
        i += 4;
        const y = data.getUint32(i, true);
        i += 4;
        const z = data.getUint32(i, true);
        i += 4;

        chunk = {
          palette: DEFAULT_PALETTE,
          size: {x: x, y: y, z: z},
        };

        chunks.push(chunk);

        i += chunkSize - (3 * 4);

      } else if (id === 'XYZI') {

        const numVoxels = data.getUint32(i, true);
        i += 4;
        chunk.data = new Uint8Array(buffer, i, numVoxels * 4);

        i += numVoxels * 4;

      } else if (id === 'RGBA') {

        const palette = [0];

        for (let j = 0; j < 256; j++) {

          palette[j + 1] = data.getUint32(i, true);
          i += 4;

        }

        chunk.palette = palette;

      } else {

        // console.log( id, chunkSize, childChunks );

        i += chunkSize;

      }

    }

    return chunks;

  }

}

class VOXMesh extends Mesh {

  constructor(chunk) {

    const data = chunk.data;
    const size = chunk.size;
    const palette = chunk.palette;

    //

    const vertices = [];
    const colors = [];

    const nx = [0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1];
    const px = [1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0];
    const py = [0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1];
    const ny = [0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0];
    const nz = [0, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0];
    const pz = [0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1];

    function add(tile, x, y, z, r, g, b) {

      x -= size.x / 2;
      y -= size.z / 2;
      z += size.y / 2;

      for (let i = 0; i < 18; i += 3) {

        vertices.push(tile[i + 0] + x, tile[i + 1] + y, tile[i + 2] + z);
        colors.push(r, g, b);

      }

    }

    // Store data in a volume for sampling

    const offsety = size.x;
    const offsetz = size.x * size.y;

    const array = new Uint8Array(size.x * size.y * size.z);

    for (let j = 0; j < data.length; j += 4) {

      const x = data[j + 0];
      const y = data[j + 1];
      const z = data[j + 2];

      const index = x + (y * offsety) + (z * offsetz);

      array[index] = 255;

    }

    // Construct geometry

    let hasColors = false;

    for (let j = 0; j < data.length; j += 4) {

      const x = data[j + 0];
      const y = data[j + 1];
      const z = data[j + 2];
      const c = data[j + 3];

      const hex = palette[c];
      const r = (hex >> 0 & 0xff) / 0xff;
      const g = (hex >> 8 & 0xff) / 0xff;
      const b = (hex >> 16 & 0xff) / 0xff;

      if (r > 0 || g > 0 || b > 0) hasColors = true;

      const index = x + (y * offsety) + (z * offsetz);

      if (array[index + 1] === 0 || x === size.x - 1) add(px, x, z, -y, r, g, b);
      if (array[index - 1] === 0 || x === 0) add(nx, x, z, -y, r, g, b);
      if (array[index + offsety] === 0 || y === size.y - 1) add(ny, x, z, -y, r, g, b);
      if (array[index - offsety] === 0 || y === 0) add(py, x, z, -y, r, g, b);
      if (array[index + offsetz] === 0 || z === size.z - 1) add(pz, x, z, -y, r, g, b);
      if (array[index - offsetz] === 0 || z === 0) add(nz, x, z, -y, r, g, b);

    }

    const geometry = new BufferGeometry();
    geometry.setAttribute('position', new Float32BufferAttribute(vertices, 3));
    geometry.computeVertexNormals();

    const material = new MeshStandardMaterial();

    if (hasColors) {

      geometry.setAttribute('color', new Float32BufferAttribute(colors, 3));
      material.vertexColors = true;

    }

    super(geometry, material);

  }

}

class VOXDataTexture3D extends DataTexture3D {

  constructor(chunk) {

    const data = chunk.data;
    const size = chunk.size;

    const offsety = size.x;
    const offsetz = size.x * size.y;

    const array = new Uint8Array(size.x * size.y * size.z);

    for (let j = 0; j < data.length; j += 4) {

      const x = data[j + 0];
      const y = data[j + 1];
      const z = data[j + 2];

      const index = x + (y * offsety) + (z * offsetz);

      array[index] = 255;

    }

    super(array, size.x, size.y, size.z);

    this.format = RedFormat;
    this.minFilter = NearestFilter;
    this.magFilter = LinearFilter;
    this.unpackAlignment = 1;
    this.needsUpdate = true;

  }

}

export {VOXLoader, VOXMesh, VOXDataTexture3D};
